Emerald Tanager

The emerald tanager is a medium-sized tanager with a length of 10.6–13 cm (4.2–5.1 in) and a mass of 18–20.5 g (0.63–0.72 oz). Both sexes are similar in appearance, but the species shows slight sexual dimorphism, with females being duller and having yellow-green instead of yellow on the head. It may be confused with the glistening-green tanager but can be told apart by its less intense plumage. It is also similar to the blue-whiskered tanager but can be distinguished by the latter's black face and throat and turquoise cheeks. Adults males are mostly bright light green, with black streaking on the upperparts. The loral area, the base of the bill, and chin, along with the auricular patch, are also black. The center and rear of the crown are dark yellow, while the rest of the crown, the region around the eye, and the band across the back of the neck are yellowish-green. The upper back is black, while the lower back, rump, and uppertail coverts are dark yellow. The wings are black and green. The underparts are mostly light green, while the center of the belly and the undertail coverts are light yellow. The iris is brown, the bill is black and the feet are bluish-gray. Immatures resemble adult females, while juveniles are much duller. …

The emerald tanager is found from southern Costa Rica to northern Ecuador; through Panama and Colombia. It may also be found in extreme southern Nicaragua. There are two disjunct populations, separated by an area between Panama and the San Juan River. Throughout its range, the emerald tanager is commonest at elevations of 500–900 m (1,600–3,000 ft) but is found at elevations of up to 1,200 m (3,900 ft) in Ecuador and as low as 100 m (330 ft) in Colombia. The average elevation inhabited is highest in the north of the range and is the lowest in the south. The emerald tanager inhabits humid lowland forest, montane evergreen forest, and secondary forest. It is usually found in the canopy and rarely strays to the forest floor. It has also been observed in lone fruiting trees or shrubs next to forests. It prefers forested habitats to semi-open ones.

The emerald tanager is omnivorous. It mainly feeds on fruit, supplementing its diet with arthropods, flowers, and flower buds. In Costa Rica, arthropods make up a greater proportion of the diet during the breeding season. The most commonly eaten fruits include those in the genera Miconia, Coussapoa, Cecropia, Ficus, Ilex, Tetrochidium, and Topobea. The emerald tanager forages singly, in pairs, or small flocks of 3–7 individuals within larger mixed-species flocks consisting of other tanager species, honeycreepers, and warblers. It is active, occasionally moving about excitedly when foraging. Fruits are typically gleaned, while insects are mainly foraged from moss in the crown of trees, with moss occasionally being torn apart during feeding to capture prey. The species has also been observed feeding on a swarm of army ants.